Here’s an excellent write-up on making a beverage carbonation system from Jeffrey Morgenthaler, bar manager of Clyde Common and drinks blogger extraordinaire. Jeffrey has published some delicious carbonated bottle cocktail recipes on his site, but gets a lot of questions about the actual act of making them fizz:

… about once a week I get an email from someone asking me how to do one of several things:

Carbonate cocktails in a way that won’t result in exploding equipment.

Carbonate ginger beer or other mixers without resorting to yeast.

Carbonate cocktails for draft delivery.

So here are the two systems that can do all of those things. Here we go.

… I was able to put together a kit that takes less than five minutes to assemble, cost me around a hundred and fifty bucks to build, and costs next to nothing to operate.

I have a SodaStream at home, but it uses expensive, proprietary refill cartridges, so I’m tempted to build a system following Jeffrey’s directions. He outlines assembling a CO2 tank, regulator, carbonator cap, and fittings to then carbonate beverages in standard plastic two liter bottles. Total cost is around $160.